Avoid undefined results when the parameter is out of range.

diff --git a/crypto/stack/stack.c b/crypto/stack/stack.c
index 2496f28a8c01b0faaf36d8355495ce249aa2855c..ff6d14a86ce5e2a997d02145b0d6ac4046c08235 100644 (file)
--- a/crypto/stack/stack.c
+++ b/crypto/stack/stack.c
@@ -306,7 +306,7 @@ int sk_num(const STACK *st)
 
 char *sk_value(const STACK *st, int i)
 {
-       if(st == NULL) return NULL;
+       if(!st || (i < 0) || (i >= st->num)) return NULL;
        return st->data[i];
 }